Several officers witnessed the incident, but could not immediately come to the woman’s aid because of the large crowd of runners, police said.

The woman was helped to her feet by other runners and continued toward Cleveland Circle.

The officers were unable to see her race number through the crowd, police said. Quinn kept running, but was eventually stopped by police officers.

He was issued a summons to appear in court to face charges of disorderly conduct and disturbing a public assembly.

Police described the injured runner as a white female age 35 to 40 with a slim build, dark hair, and dark-colored running gear.

It could not be determined yesterday how serious her injuries were. A woman who answered a number listed for Quinn said only, “I’m sorry, no, thank you,’’ when asked about the allegations against him.

Jack Fleming — a spokesman for the Boston Athletic Association, which organizes the marathon — said race officials were cooperating with authorities.

He had no information yesterday on the woman’s identity or the extent of her injuries.

Fleming said that there were several first aid stations between the finish line and the spot where the incident occurred. He said that the woman may have sought medical attention at one of those stations. “Sometimes these things do take a day or two or three to surface,’’ he said.

Authorities are urging the injured runner and any witnesses to call Boston police detectives at 617-343-4335.